package com.youngdatafan.dataintegration.core.util.encryption.sm;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

/**
 * sm4 实现类.
 *
 * @author gavin
 */
public class Sm4 {
    public static final int SM4_ENCRYPT = 1;

    public static final int SM4_DECRYPT = 0;

    public static final byte[] SBOX_TABLE = {(byte) 0xd6, (byte) 0x90, (byte) 0xe9, (byte) 0xfe,
        (byte) 0xcc, (byte) 0xe1, 0x3d, (byte) 0xb7, 0x16, (byte) 0xb6,
        0x14, (byte) 0xc2, 0x28, (byte) 0xfb, 0x2c, 0x05, 0x2b, 0x67,
        (byte) 0x9a, 0x76, 0x2a, (byte) 0xbe, 0x04, (byte) 0xc3,
        (byte) 0xaa, 0x44, 0x13, 0x26, 0x49, (byte) 0x86, 0x06,
        (byte) 0x99, (byte) 0x9c, 0x42, 0x50, (byte) 0xf4, (byte) 0x91,
        (byte) 0xef, (byte) 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43,
        (byte) 0xed, (byte) 0xcf, (byte) 0xac, 0x62, (byte) 0xe4,
        (byte) 0xb3, 0x1c, (byte) 0xa9, (byte) 0xc9, 0x08, (byte) 0xe8,
        (byte) 0x95, (byte) 0x80, (byte) 0xdf, (byte) 0x94, (byte) 0xfa,
        0x75, (byte) 0x8f, 0x3f, (byte) 0xa6, 0x47, 0x07, (byte) 0xa7,
        (byte) 0xfc, (byte) 0xf3, 0x73, 0x17, (byte) 0xba, (byte) 0x83,
        0x59, 0x3c, 0x19, (byte) 0xe6, (byte) 0x85, 0x4f, (byte) 0xa8,
        0x68, 0x6b, (byte) 0x81, (byte) 0xb2, 0x71, 0x64, (byte) 0xda,
        (byte) 0x8b, (byte) 0xf8, (byte) 0xeb, 0x0f, 0x4b, 0x70, 0x56,
        (byte) 0x9d, 0x35, 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, (byte) 0xd1,
        (byte) 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, (byte) 0x87,
        (byte) 0xd4, 0x00, 0x46, 0x57, (byte) 0x9f, (byte) 0xd3, 0x27,
        0x52, 0x4c, 0x36, 0x02, (byte) 0xe7, (byte) 0xa0, (byte) 0xc4,
        (byte) 0xc8, (byte) 0x9e, (byte) 0xea, (byte) 0xbf, (byte) 0x8a,
        (byte) 0xd2, 0x40, (byte) 0xc7, 0x38, (byte) 0xb5, (byte) 0xa3,
        (byte) 0xf7, (byte) 0xf2, (byte) 0xce, (byte) 0xf9, 0x61, 0x15,
        (byte) 0xa1, (byte) 0xe0, (byte) 0xae, 0x5d, (byte) 0xa4,
        (byte) 0x9b, 0x34, 0x1a, 0x55, (byte) 0xad, (byte) 0x93, 0x32,
        0x30, (byte) 0xf5, (byte) 0x8c, (byte) 0xb1, (byte) 0xe3, 0x1d,
        (byte) 0xf6, (byte) 0xe2, 0x2e, (byte) 0x82, 0x66, (byte) 0xca,
        0x60, (byte) 0xc0, 0x29, 0x23, (byte) 0xab, 0x0d, 0x53, 0x4e, 0x6f,
        (byte) 0xd5, (byte) 0xdb, 0x37, 0x45, (byte) 0xde, (byte) 0xfd,
        (byte) 0x8e, 0x2f, 0x03, (byte) 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b,
        0x51, (byte) 0x8d, 0x1b, (byte) 0xaf, (byte) 0x92, (byte) 0xbb,
        (byte) 0xdd, (byte) 0xbc, 0x7f, 0x11, (byte) 0xd9, 0x5c, 0x41,
        0x1f, 0x10, 0x5a, (byte) 0xd8, 0x0a, (byte) 0xc1, 0x31,
        (byte) 0x88, (byte) 0xa5, (byte) 0xcd, 0x7b, (byte) 0xbd, 0x2d,
        0x74, (byte) 0xd0, 0x12, (byte) 0xb8, (byte) 0xe5, (byte) 0xb4,
        (byte) 0xb0, (byte) 0x89, 0x69, (byte) 0x97, 0x4a, 0x0c,
        (byte) 0x96, 0x77, 0x7e, 0x65, (byte) 0xb9, (byte) 0xf1, 0x09,
        (byte) 0xc5, 0x6e, (byte) 0xc6, (byte) 0x84, 0x18, (byte) 0xf0,
        0x7d, (byte) 0xec, 0x3a, (byte) 0xdc, 0x4d, 0x20, 0x79,
        (byte) 0xee, 0x5f, 0x3e, (byte) 0xd7, (byte) 0xcb, 0x39, 0x48};

    public static final int[] FK = {0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc};

    public static final int[] CK = {0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
        0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
        0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
        0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
        0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
        0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
        0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
        0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279};

    private long getUlongBe(final byte[] b, final int i) {
        return (long) (b[i] & 0xff) << 24 | (long) ((b[i + 1] & 0xff) << 16) | (long) ((b[i + 2] & 0xff) << 8) | (long) (b[i + 3] & 0xff) & 0xffffffffL;
    }

    private void putUlongBe(final long n, final byte[] b, final int i) {
        b[i] = (byte) (int) (0xFF & n >> 24);
        b[i + 1] = (byte) (int) (0xFF & n >> 16);
        b[i + 2] = (byte) (int) (0xFF & n >> 8);
        b[i + 3] = (byte) (int) (0xFF & n);
    }

    private long shl(final long x, final int n) {
        return (x & 0xFFFFFFFF) << n;
    }

    private long rotl(final long x, final int n) {
        return shl(x, n) | x >> (32 - n);
    }

    private void swap(final long[] sk, final int i) {
        long t = sk[i];
        sk[i] = sk[31 - i];
        sk[31 - i] = t;
    }

    private byte sm4Sbox(final byte inch) {
        int i = inch & 0xFF;
        return SBOX_TABLE[i];
    }

    private long sm4Lt(final long ka) {
        byte[] a = new byte[4];
        byte[] b = new byte[4];
        putUlongBe(ka, a, 0);
        b[0] = sm4Sbox(a[0]);
        b[1] = sm4Sbox(a[1]);
        b[2] = sm4Sbox(a[2]);
        b[3] = sm4Sbox(a[3]);
        long bb = getUlongBe(b, 0);
        return bb ^ rotl(bb, 2) ^ rotl(bb, 10) ^ rotl(bb, 18) ^ rotl(bb, 24);
    }

    private long sm4F(final long x0, final long x1, final long x2, final long x3, final long rk) {
        return x0 ^ sm4Lt(x1 ^ x2 ^ x3 ^ rk);
    }

    private long sm4CalciRK(final long ka) {
        byte[] a = new byte[4];
        byte[] b = new byte[4];
        putUlongBe(ka, a, 0);
        b[0] = sm4Sbox(a[0]);
        b[1] = sm4Sbox(a[1]);
        b[2] = sm4Sbox(a[2]);
        b[3] = sm4Sbox(a[3]);
        long bb = getUlongBe(b, 0);
        return bb ^ rotl(bb, 13) ^ rotl(bb, 23);
    }

    private void sm4Setkey(final long[] sk, final byte[] key) {
        long[] mk = new long[4];
        final long[] k = new long[36];
        mk[0] = getUlongBe(key, 0);
        mk[1] = getUlongBe(key, 4);
        mk[2] = getUlongBe(key, 8);
        mk[3] = getUlongBe(key, 12);
        k[0] = mk[0] ^ (long) FK[0];
        k[1] = mk[1] ^ (long) FK[1];
        k[2] = mk[2] ^ (long) FK[2];
        k[3] = mk[3] ^ (long) FK[3];
        int i = 0;
        for (; i < 32; i++) {
            k[i + 4] = k[i] ^ sm4CalciRK(k[i + 1] ^ k[i + 2] ^ k[i + 3] ^ (long) CK[i]);
            sk[i] = k[i + 4];
        }
    }

    private void sm4OneRound(final long[] sk, final byte[] input, final byte[] output) {
        long[] ulbuf = new long[36];
        ulbuf[0] = getUlongBe(input, 0);
        ulbuf[1] = getUlongBe(input, 4);
        ulbuf[2] = getUlongBe(input, 8);
        ulbuf[3] = getUlongBe(input, 12);
        int i = 0;
        while (i < 32) {
            ulbuf[i + 4] = sm4F(ulbuf[i], ulbuf[i + 1], ulbuf[i + 2], ulbuf[i + 3], sk[i]);
            i++;
        }
        putUlongBe(ulbuf[35], output, 0);
        putUlongBe(ulbuf[34], output, 4);
        putUlongBe(ulbuf[33], output, 8);
        putUlongBe(ulbuf[32], output, 12);
    }

    private byte[] padding(final byte[] input, final int mode) {
        if (input == null) {
            return null;
        }

        byte[] ret;
        if (mode == SM4_ENCRYPT) {
            int p = 16 - input.length % 16;
            ret = new byte[input.length + p];
            System.arraycopy(input, 0, ret, 0, input.length);
            for (int i = 0; i < p; i++) {
                ret[input.length + i] = (byte) p;
            }
        } else {
            int p = input[input.length - 1];
            ret = new byte[input.length - p];
            System.arraycopy(input, 0, ret, 0, input.length - p);
        }
        return ret;
    }

    /**
     * sm4SetkeyEnc.
     *
     * @param ctx Sm4Context
     * @param key key
     */
    public void sm4SetkeyEnc(Sm4Context ctx, byte[] key) {
        if (ctx == null) {
            throw new NullPointerException("ctx is null!");
        }

        if (key == null || key.length != 16) {
            throw new NullPointerException("key error!");
        }

        ctx.setMode(SM4_ENCRYPT);
        sm4Setkey(ctx.getSk(), key);
    }

    /**
     * sm4SetkeyDec.
     *
     * @param ctx Sm4Context
     * @param key key
     */
    public void sm4SetkeyDec(Sm4Context ctx, byte[] key) {
        if (ctx == null) {
            throw new NullPointerException("ctx is null!");
        }

        if (key == null || key.length != 16) {
            throw new NullPointerException("key error!");
        }

        int i;
        ctx.setMode(SM4_DECRYPT);
        sm4Setkey(ctx.getSk(), key);
        for (i = 0; i < 16; i++) {
            swap(ctx.getSk(), i);
        }
    }

    /**
     * sm4CryptEcb.
     *
     * @param ctx   Sm4Context
     * @param input input
     * @return ecb data
     * @throws IOException io error
     */
    public byte[] sm4CryptEcb(Sm4Context ctx, byte[] input) throws IOException {
        byte[] newInput = input;
        if (newInput == null) {
            throw new NullPointerException("input is null!");
        }

        if ((ctx.isPadding()) && (ctx.getMode() == SM4_ENCRYPT)) {
            newInput = padding(newInput, SM4_ENCRYPT);
        }

        int length = newInput.length;
        ByteArrayInputStream bins = new ByteArrayInputStream(newInput);
        ByteArrayOutputStream bous = new ByteArrayOutputStream();
        for (; length > 0; length -= 16) {
            byte[] in = new byte[16];
            byte[] out = new byte[16];
            bins.read(in);
            sm4OneRound(ctx.getSk(), in, out);
            bous.write(out);
        }

        byte[] output = bous.toByteArray();
        if (ctx.isPadding() && ctx.getMode() == SM4_DECRYPT) {
            output = padding(output, SM4_DECRYPT);
        }
        bins.close();
        bous.close();
        return output;
    }

    /**
     * sm4CryptCbc.
     *
     * @param ctx   Sm4Context
     * @param iv    iv
     * @param input input
     * @return cbc data
     * @throws IOException io error
     */
    public byte[] sm4CryptCbc(Sm4Context ctx, byte[] iv, byte[] input) throws IOException {
        byte[] newInput = input;
        if (iv == null || iv.length != 16) {
            throw new NullPointerException("IV error!");
        }

        if (newInput == null) {
            throw new NullPointerException("input is null!");
        }

        if (ctx.isPadding() && ctx.getMode() == SM4_ENCRYPT) {
            newInput = padding(newInput, SM4_ENCRYPT);
        }

        int i;
        int length = newInput.length;
        ByteArrayInputStream bins = new ByteArrayInputStream(newInput);
        ByteArrayOutputStream bous = new ByteArrayOutputStream();
        if (ctx.getMode() == SM4_ENCRYPT) {
            for (; length > 0; length -= 16) {
                byte[] in = new byte[16];
                byte[] out = new byte[16];
                byte[] out1 = new byte[16];

                bins.read(in);
                for (i = 0; i < 16; i++) {
                    out[i] = (byte) (in[i] ^ iv[i]);
                }
                sm4OneRound(ctx.getSk(), out, out1);
                System.arraycopy(out1, 0, iv, 0, 16);
                bous.write(out1);
            }
        } else {
            byte[] temp = new byte[16];
            for (; length > 0; length -= 16) {
                byte[] in = new byte[16];
                byte[] out = new byte[16];
                byte[] out1 = new byte[16];

                bins.read(in);
                System.arraycopy(in, 0, temp, 0, 16);
                sm4OneRound(ctx.getSk(), in, out);
                for (i = 0; i < 16; i++) {
                    out1[i] = (byte) (out[i] ^ iv[i]);
                }
                System.arraycopy(temp, 0, iv, 0, 16);
                bous.write(out1);
            }
        }

        byte[] output = bous.toByteArray();
        if (ctx.isPadding() && ctx.getMode() == SM4_DECRYPT) {
            output = padding(output, SM4_DECRYPT);
        }
        bins.close();
        bous.close();
        return output;
    }
}
